Garett Bolles (72) of the Denver Broncos celebrates a rushing touchdown by Trevor Siemian (13) against the Los Angeles Chargers during the second quarter on Monday, Sept. 11, 2017. The Denver Broncos hosted the Los Angeles Chargers.

Two years ago, an NFL executive surveyed the college landscape and offered an associate in the industry some friendly advice. “You better hit on an offensive lineman now,” the executive told his pal, because he could see the supply of capable blockers dwindling.

The words seem prophetic after the dismal product the NFL rendered in Week 1. The league has for years fretted over a scarcity of capable quarterbacks, and starting appearances from the likes of Tom Savage and Scott Tolzien on Sunday highlighted the notion there are more NFL teams than competent professional quarterbacks in existence.

But an equally alarming problem surfaced as offenses reached new levels of putridity. It was not only the men throwing the ball, but also the men charged with protecting them. The NFL is amid an offensive line crisis, and the talent drain at the position is damaging the quality on the field in even uglier fashion than poor quarterbacking.

“I believe that the lineman shortage is a bigger problem,” said the executive, who requested anonymity to speak candidly. “I don’t know if I can compare the two. They’re both not real good.”

“I hope the play gets better as the year goes on,” said nine-year NFL lineman Geoff Schwartz, now a SiriusXM NFL Radio analyst. “There’s some young offensive lines that need to get better. There is an issue with a lack of just good offensive linemen in the NFL.”

In April’s draft, the NFL regarded the latest crop of linemen and decided, “No, thanks.” Only two offensive linemen — tackles Garrett Boles and Ryan Ramczyk — were taken in the first round. None was taken until the Broncos grabbed Boles with the 20th pick, the latest in modern NFL history the draft had gone without an offensive lineman.

“There’s not much offensive line talent coming into the league,” the executive said. “What were the top offensive linemen, they’re not there.”

Those within the league believe the dearth of serviceable blockers derives from two primary factors: Offensive linemen enter the NFL less prepared than ever, and they have less opportunity to improve once they’re in the league.

The college spread offense, a frequent object of scorn among NFL evaluators, plays a major role. Most offensive linemen play in systems reliant on screens, quick passes and misdirection, which means they enter the NFL accustomed to rarely hitting beyond their initial block, or having had to thwart a pass rusher’s secondary moves.

“The tempo is so fast in college now that the techniques just aren’t taught like they used to be,” Schwartz said. “Now, it’s about guys trying to get back to the line of scrimmage and not finish. The spread offenses are nothing like the offenses you run in the NFL, so guys come in just not as prepared.”

From the youth level through college, players participate year-round in noncontact, seven-on-seven leagues and clinics for quarterbacks and skill players. The same opportunities do not exist for offensive lineman, at least in any meaningful way.

“There’s a lot of college offensive linemen that have never been in a three-point stance,” the executive said. “The pro game is different. I get football is football. There’s a lot more emphasis on different techniques and fundamentals in college.”

Under the new collective bargaining agreement, teams have fewer offseason practices and hit at full speed less often when they do practice. The decrease of full-speed offseason practicing hurts offensive lines more than any other unit, especially in comparison with defensive linemen.

“You have to learn how to block,” the executive said. “Getting after a passer, getting up field, it doesn’t have to be as refined as offensive line play. There is far less time to develop skills that can only be developed through contact.”

The rash of awful offensive line play may improve as lines get more repetitions together at game speed. But horrific offensive line play led to a hideous Week 1.

Six teams failed to crack double-digit points and two others, the Jets and Saints, didn’t score a touchdown. As Gregg Rosenthal noted at NFL.com, 14 offenses gained less than than 300 yards in Week 1, accounting for 46 percent of the league. That didn’t occur with such frequency in any week last year, and only 22 percent of offenses gained less than 300 yards in the previous three Week 1s. Last year, only the Rams averaged less than 300 yards for the season.

A lack of offensive production isn’t an inherent problem. The problem is the nature of how offenses have bogged down. It is one thing for a stout defense to thwart passable offensive execution. It is another when defensive lines are shoving offensive linemen five yards into the backfield and ruining any semblance of offensive play design. It makes games painful to watch — it stops looking like football and starts looking like survival. In too many games, possessions unfolded as spasms of panic capped with a punt.

“The overall product itself is not of the quality I’m used to seeing, that I grew up watching,” Seattle wide receiver Doug Baldwin said in an interview on SiriusXM. “As far as a solution, I have no idea. I’m interested to see what happens, because I do believe a quality drop-off has happened.”

The marquee games Sunday were Packers-Seahawks and Cowboys-Giants. In both, an inept offensive line prevented any attempt to commit football. Russell Wilson ran for his life behind Seattle’s overwhelmed blockers, and Eli Manning chucked desperate, short passes behind a blue-and-gray sieve.

Atrocious offensive line play, in many ways, harms the viewing experience more than terrible quarterback play. A cruddy quarterback behind an adequate line will make bad decisions and poor throws and fail to score points, but those mistakes occur within the flow of an otherwise pleasant game. An adequate quarterback behind a horrible line doesn’t even have the chance to initiate what fans would recognize as football. He’s just engulfed by chaos.

The Seahawks were not alone. According to Pro Football Focus, 10 teams received a positive grade on passing blocking and 11 were above zero in run blocking. In game after game, an offensive line gave its offense no chance.

The drop in quality line play has already reshaped NFL offenses, in subtle fashion. Last year, quarterbacks averaged 8.25 yards per throw in the air, the shortest average pass in the past decade, at least. Running backs and slot receivers are catching more passes than at any point in recent memory. Quarterbacks and coordinators have little choice — with less time to throw, dump-offs and checkdowns are the best, safest options.

The NFL is fundamentally changing, for the worse. It could use more and better quarterbacks. It more badly needs better linemen to protect them, to give them a chance and to make the sport palatable.

The Broncos last spring entered the middle rounds of the NFL draft on the hunt for game-breaking talent. And when Carlos Henderson (third-round pick) and Isaiah McKenzie (fifth) started making plays under the glaring August sun at training camp, it appeared Denver would have a youthful injection to its sagging offense in 2017.